The present invention relates to an electrophotographic copying machine and, more particularly, to an optical apparatus for an electrophotographic copying machine of the type able to make copies at different magnification.
An electrophotographic copying machine produces an electrostatic latent image on a photoreceptor corresponding to a pattern image on a document such as a manuscript or book to be copied. Toner particles are electrostatically adhered to the latend image, so that the latent image becomes visible as a toner image. The toner image on the photoreceptor is transferred onto a copy paper via a transference charger.
In some types of electrophotographic copying machines, there is employed an optical apparatus comprising a plurality of mirrors and an objective lens assembly for forming an image of an original to be copied on the photoreceptor. The plurality of mirrors and the objective lens assembly are moved to change magnification of the original image.
Conventionally, a lens and mirrors must be moved independently so that the optical apparatus becomes complex. Therefore, it is desired to provide an improved simplified optical apparatus.